This invention relates generally to portable toilets and recreational vehicle toilets. More particularly, the invention relates to a toilet incorporating a flush assembly that in which, a reduced amount of pressure to achieve proper flushing of the toilet is a desirable characteristic.
It is conventional practice when flushing toilets of the type to which this invention relates to utilize either manually operable pump or a battery operated pump for pumping fresh flush water from a flush water source into the toilet bowl. Manual pumps are low cost items which often employ bellows. In a bellows operated pump, it is typically necessary for the user to apply about a thirty-five pound of force to the bellows to operate the pump. If the force is too hard or sudden, flush water is shot out of a discharge nozzle and out of the toilet bowl. If an insufficient force is applied to the bellows, a less than satisfactory flush is obtained. While manual pumps have proven satisfactory for the needs of some users, handicapped, elderly and young persons generally do not have the physical strength or ability to operate a bellow pump. For these users, power assisted flush assemblies have been developed.
An electric or power assisted flush assembly requires less force on the actuator than a manual pump and achieves repeated uniform wetting and thorough flushing of the toilet's bowl while providing for an efficient use of the flush water supply. U.S. Pat. No. 4,926,508 illustrates a toilet which incorporates a power assisted flush assembly.
Part of the reason for the amount of flushing force which is necessary is that a check valve is typically incorporated into the discharge nozzle to prevent inadvertent leaking of flush water from the source. Check valves generally use a coil or compression spring to force a valve disc into sealing engagement with a valve seat. Because of the spring, the amount of force necessary to open the check valve is less than the force needed to maintain it open. Thus, the required force to maintain the valve open increases as the valve disc is disengaged or unseated from the valve seat.
In toilets having manually operated flush mechanisms, such a restriction is not objectionable because the same large force that is necessary to operate the flush mechanism is sufficient to initially open the check valve and maintain it open until flushing is completed. However, this resistance is often of a magnitude that results in the quick depletion of the battery source or power of the assisted flush assembly. One objective of a power assisted flush assembly is therefore to use as little power as possible during flushing so as not to significantly drain the power source. In fact, in some power assisted flush assemblies this has led to the replacement of the check valve with a manually operated valve, formed with the flush assembly so as to operate off of the "push" force required to actuate flushing itself. This again poses a problem for the elderly, the young and other persons who generally do not have the physical strength or ability to operate the mechanical aspect of the pump.
The above mentioned manual valve normally remains closed and is incorporated into the pump. The valve is manually opened during initiation of a flush by the same actuator movement that closes the switch that in turn initiates the power assisted flush. Unfortunately, this valve increases the complexity of the flushing assembly and requires eliminating the check valve from an otherwise identically setup toilet, further increasing the production costs.
In view of the above limitations, it is a principal object of this invention to provide a RV toilet which requires a reduced flushing force with either a manual pump or a power assisted pump.
Another object of the invention is to incorporate a check valve with minimum flow restrictions into a toilet which is equally usable with either a manually operable pump assembly or a power assisted pump assembly.
Yet another object of this invention is to provide a toilet which has an improved flushing action, a more efficient use of flush water and which allows for more efficient use of the power supply when equipped with a power assisted pump assembly.
Still another object of the present invention is to provide a toilet having a check valve which requires less force to maintain open than it does to initially open.
A further object of this invention is to provide a toilet with a check valve that does not rely on a spring to maintain the check valve assembly in its closed position.
It is also an object of this invention to provide a toilet with a check valve that utilizes a magnet to maintain the check valve assembly in its closed position.